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Re: -mfused-madd vs -ffp-contract deprication?
Richard Henderson <rth@redhat.com> writes:
> On 11/08/2010 02:58 PM, Joseph S. Myers wrote:
>> <http://gcc.gnu.org/ml/gcc-patches/2010-10/msg01884.html>:
>> Existing target options may sometimes be ambiguous as to whether they are
>> meant to disable instructions that might not be available, or to disable
>> automatic conversion
>
> It's currently used in:
>
> xtensa
> i386
> s390
> rs6000
> mips
> ia64
>
> Given that MIPS doesn't implement true FMA, MIPS probably should
> match the (plus (mult a b) c) pattern unconditionally (modulo ISA)
> and be done with it.
I think they should still be conditional on TARGET_FUSED_MADD
because of the R8000 case. If anyone is still using bleeding edge
GCC on R8000, we might as well continue to provide a way for them
to disable the fusing.
Richard